WASHINGTON - As President Bush's health chief, Tommy Thompson proudly trumpeted millions of taxpayer dollars to help workers exposed to toxic debris at the World Trade Center site after the Sept. 11 attacks, even amid complaints that his agency was not doing enough.

Now, Thompson's private company has won an $11 million contract to treat some of those same ground zero responders - the latest twist in a fitful government effort to determine how many people were sickened by the debris, and to care for them.

The contract awarded by the Centers for Disease Control and Prevention aims to track the health of 4,000 to 6,000 workers who live outside the New York City area, where a separate health-monitoring program is in place. The CDC is part of the Health and Human Services Department, which Thompson headed in Bush's first term.

Internal e-mail messages obtained by the Associated Press show that the one-year contract went to Logistics Health Inc. of La Crosse, Wis. Thompson is the company's president.

As HHS secretary, Thompson was pressed by New York lawmakers to take a more active and aggressive role in tracking and treating Sept. 11-related health problems.

Logistics Health's chief operating officer, Bill Vandervennet Jr., said the company won the contract "because of our proven experience."

In the years since the 2001 attacks, studies show that workers who toiled at the site have had higher-than-normal rates of lung problems and post-traumatic stress. Others have reported an increase in gastrointestinal disorders.

Four companies bid for the CDC contract, officials said. It went to Logistics Health based on "an evaluation of everything from cost to technical abilities to past performance," CDC spokeswoman Bernadette Burden said. Thompson's company already provides some medical services for the Army.

Logistics Health will provide annual exams to trade center responders around the country, diagnose and treat Sept. 11-related conditions, and provide a pharmacy benefit to those responders.